Exhaust silencing and spark arresting device



April 9, 1940. R. L. HOYLE EXHAUST SILENCING AND SPARK ARRESTING DEVICE 5 Sheets-Sheet 1 Filed March 21, 1938 April 9, 1940. R. L. HOYLE 2,195,920

EXHAUST SILENCING AND SPARK ARRESTING DEVICE Filed Marc 11 21, 1958 3 Shets-Sheet 2 ooo'ooooo April 940. R. HOYLE 2,196,920

EXHAUST SILENCING AND SPARK ARRESTING DEVICE Filed March 21, 1938 3 Sheets-Sheet 3 five/24 0,71 @Zy 9 2 0562? oz- /zqyk Patented Apr. 9, 1940 UNITED STATES PATENT OFFICE v EXHAUST SILENCING AND SPARK ABBESTHWG DEVICE Application March 21,

12 Claims.

This invention relates to a combination exhaust silencer and spark arrester for internal combustion engines. The operation of an internal combustion engine usually is accompanied by the discharge of heated solid particles, principally particles of incandescent carbon, from the exhaust. The engines are used-in many situations where it is desired to guard carefully against all fire hazards. For example, such is the case where the engines are used aboard ship, near gas wells or gasoline refineries, and also where they are employed for the operation of tractors. In view of the fire hamrd created by the incandescent particles, such engines are usually equipped with spark arresters.

It is the object of the present invention to provide a simple and economical construction tor accomplishing both the silencing and the spark arresting functions, this object being accomplished. by utilizing the same structure for silencing the exhaust gases and separating the heated solid particles from them.

Briefly, the purposes of the invention are accomplished by providing a chamber in which the exhaust gases reverse their direction of flow several times, these fiow reversals contributing substantially to the silencing function and also causing the solidpartlcles to become separated from the exhaust gas stream by centrifugal action. A baiile member is arranged in the lower portion of the chamber in such a manner as to provide a zone of quiescence out of the gas stream and to cause the solid particles to be deposited therein. Means are provided for retaining the particles in this zone and for removing them periodically.

3 view of a further modification of the invention;

Fig. '1 is a longitudinal sectional view of a still further modification, taken along line 1-1 of Fig. 8:

Fig. 8 is a transverse sectional view along line 8-4 of Fig. '1; and a Fig. l0'is a fragmental section along line i0l0 of Fig. 9.

The device shown in Figs. 1 and 2 is adapted to be disposed vertically, and the exhaust gases to travel vertically upward. It is understood that 1938, Serial No. 197,133

in the specification and the claims the words horizontal and vertical are not used in a restrictive sense, and any deviation from the horizontal or vertical arrangement which is not sufllcient to disturb the principle oi. operation as it is described herein, is within the scope of the invention. The cylindrical casing I0 is provided with end-walls II and I2, end wall I2 being provided with a flanged outlet opening it. Spaced interiorly from outlet end wall I! is a substantially disc-shaped partition i4, and spaced interlorly from inlet end wall ii is frusto-conical partition or baiile member l5. Partition ll divides the interior of the easing into chambers I1 and I8 and baille member I! defines a zone of quiescence it in the lower portion of chamber H, as will be described hereinafter. Baflie member I 5 and end wall II have substantially central openings therein and an open-ended imperi'orate inlet tube i9 is mounted in these openings and extends part-way through chamber l1.

. Partition ll has two eccentric openings within which are mounted the upper ends oi! foraminous open-ended outlet tubes 20, these tubes being 01!- set with respect to inlet tube i9 and extending part-way through chamber ii to a point adjacent baflle member II. The inlet and outlet tubes are arranged inadiacent side by side relation throughout a portion of their-length within chamber ii. The upper partition I 4 has a, substantially central, blunt downward projection 2 l, and bailie member i5 has a series of spaced circumferentially-elongated slots 22 therein adjacent the outer portion thereof which adjoins the cylindrical wall of casing ill. The bottom end wall of the casing has a clean-out opening therein which is normally closed by a threaded plug 23.

As stated heretofore, the casing and tubes are arranged vertically and in operation, the exhaust gases enter and pass upwardly through inlet tube IS. A small proportion of the gases emergingfrom tube i9 pass laterally from the end of inlet tube I! through the perforations of tubes 20 and into said tubes, but the predominant proportion reverse their direction within chamber i1 and flow downwardly. The projection 2| of partition I4 assists in directing the gas flow during this reversal. The gases again reverse their direction in the bottom portion of chamber ii and enter the lower ends of outlet tubes 20. At the first reversal of direction a small proportion of the solid particles may be thrown out of the gas stream by centrifugal action and drop upon the upper surface of battle member l5. While the gases are flowing downwardly within chamber 5?, they are free to spread out across the transverse area of the chamber and their velocity is greatly decreased. The force of gravity causes some of the particles to descend faster than the gases and they are thus separated from the gas stream. At the second reversal of direction at the bottom of the chamber centrifugal action and the force of gravity combine to accomplish an effective separation of the particles from the stream. and the particles drop upon the baiiie member I 5. The particles on baiile member l5 are agitated more or less actively by the movement of the gas, and descend the inclined surface of said bailie member and pass into space it through slots 22. Baffle member 15 protects the space i6 below it from the gas streams and turbulence Within chamber I1, and maintains such space as a zone of quiescence and prevents the particles therein from being swept up again by the gas stream. The particles collect upon the bottom end wall H of the casing and may be removed periodically through the opening in said wall by unscrewing plug 23. Slots 22 also serve to connect space l6 with the path of noises and gas in chamber l1, whereby space I6 functions as a resonator and exerts a silencing action. The gases after leaving outlet tubes. converge in upper chamber i8 and pass out of the device through outlet opening l3.

It is apparent that the invention provides, in a simple and economical manner, an effective means for silencing and removing the heated solid particles from the gases. The expansion and reversal of direction of the gases in chamber I'l, together with the resonator action of space l6, combine to provide eifective silencing. The arrangement of the baffle member i5 is such that it does not restrict the gas flow within the chamher, and does not resort to the flow-obstructin principle so frequently used in spark arrestors. Although the gases undergo two reversals of direction, this is done with a minimum restriction because they take place within the comparatively open volume of chamber l1. Chamber IT is relatively small, and both reversals take place comparatively close together, whereby the size and cost of the equipment is reduced accordingly. The simplicity of the interior arrangement is evident, comprising as it does merely the three tubes, the partition l4 and the baiile member l5. This factor of simplicity contributes considerably toward the reduction of the cost of the device.

The construction shown in Figs. 3 and 4 is closely related to that of Figs. 1 and 2 and comprises a cylindrical casing 25 adapted to be disposed with its longitudinal axis extending vertically. The single inlet tube 26 and the two outlet tubes 21 are arranged eccentrically of the casing. This tube arrangement is shown in Fig. 4. This arrangement may be varied. and any one of the tubes may be arranged concentrically with the casing if desired. The inlet tubes extend laterally adjacent the outlet tubes for a portion of their length, and are in contact with the outlet tubes and joined to them, as by welding, whereby the tubes contribute to their mutual support within the casing.

A baflle member 28 is supported within the low er end of the casing by means of inlet tube 26, the baflie member being substantially conical in shape and cut out to accommodate the inlet tube, the base of the cone extending toward the cylindrical wall 25 of the casing but being spaced therefrom to form an annular opening into the zone of quiescence below the baiiie member. In-

let tube 26 is imperforate from the inlet end thereof to a point above baiile member 28, as shown and is foraminous from that point to its upper end. A transverse partition 30 extends across the interior of the casing at a point spaced above the outlet end of inlet tube 26. to define a resonating chamber or expansion chamber 3| in the upper portion of the casing. The outlet tubes 21 are imperforate and pass through partition 30 and directly through the outlet end wall of casing 25. Each outlet tube has one or more relatively large openings 32 therein within chamber 3| to provide communication between the interior of the tubes and the chamber. The lower end wall 33 of the casing is bolted in position as shown and may be removed for cleaning out the solid particles by loosening the bolts 34.

The operation of this modification is substantially similar to that described in connection with the construction of Figs. 1 and 2. In this modification, however, the gases cannot pass laterally through the walls of the outlet tubes because the latter are imperforate. This construction has been found to operate satisfactorily.

The modification of Fig. 5 comprises a vertically disposed cylindrical casing 36 having inlet and outlet end walls 31 and 38 and transverse partition 39 therein separating the easing into chambers 40 and 4|. An inclined baiile member comprising two plate sections 42 and 41 is located in the lower portion of chamber 40. These two plate sections are inclined downwardly toward each other, the lower portion of section 43 overlying the lower portion of section 42 and being spaced therefrom to form opening 44 for the deposit of solid particles into the zone of quiescence. The overlying relation of section 43 to section 42 protects the opening 44 and the space within the zone of quiescence from the movement of gases within the casing to a greater extent than does a plain opening which is formed by having the bottom edges of the two sections at the same level. A vertical partition 45 extends between the bottom end wall 31 of the casing and bai'lie section 42 and confines the solid particles to a restricted zone of quiescence 46. A foraminous open-ended inlet tube 41 passes through inlet end wall 3! and baffle section 42 and part-way through chamber 40, and an open-ended outlet tube 48 passes through outlet end wall 38 and partition 39 and part-way through chamber 40. Outlet tube 48 is foraminous throughout its length in chamber 40 and a portion of its length in chamber 4|. These tubes are offset laterally with respect to each other and extend laterally adjacent each other throughout a portion of their length within chamber 40. The space 49 adjacent the zone of quiescence 46 forms a resonating chamber or expansion chamber surrounding inlet tube 41.

The bottom wall 31 has a clean-out opening 50 therein providing access to the chamber 46 within which the particles are deposited. This opening is normally closed by means of a plate 5| which has a threaded rod 52 projecting downwardly-therefrom. Plate 6| is held in place by means of bracket member 53 against which the nut 54 is threaded. When it is desired to remove the particles from the chamber 46 the cover 5| is removed in the manner well known for covers of this type.

Means is provided for quenching the incandescent particles. An opening 55 is provided in the wall of chamber 44 adjacent the lower end por- 'tion of the side of outlet tube 48 which is remote from inlet tube 41-. A bushing 55 is mounted, as by welding at the opening 55 and a nozzle 51 which is provided with a number of small Jets is mounted in the bushing and projects into chamber 48. A water supply pipe or hose 58 is connected to the nozzle 51. Water may be sprayed into chamber 48 in the space between the casing wall and tubes 41 and 48, creating a mist in the lower portion oi. chamber 48 which descends upon baiile sections 42 and '43 and collects in bottom chamber 48. In the course of this action the water contacts and quenches the incandescent particles and assists in separating them from the gas stream. An opening 58 is provided in the bottom portion of the wall of chamber 45 for draining the water from the device, which opening may be closed by a plug 58- when the water snray is not in use.

The operation of this device is similar to that of the modification shown in Figs. 3 and 4 with the addition of the action of the water spray, as described heretofore.

In Fig. 6 is shown a modification of the construction of Fig. 5. Only the bottom portion of the casing 55 is shown, with an open-ended inlet tube 56 extending upwardly and an open-ended outlet tube 51 extending downwardly into the same. The baiile member is a single plate 68 which is inclined downwardly from the wall of the chamber at the side adjacent the end of the outlet tube 81 to the portion through which the inlet tube extends. Inlet tube 55 is imperforate to a point above the baffle member 58 as shown and is ioraminous from that point to the upper end. An opening 58 is provided between the lower end of the' plate 88 and the wall of casing 55 at the side remote from outlet tube 51. A portion of the bottom end wall of the casing is depressed downwardly as shown at 18, and the clean-out opening II is located in this portion. The opening is closed by removable cover 12, similar to the cover 5| of Fig. 5. The sloping walls of the depressed portion 18 cause the solid particles to collect in the space above clean-out opening 1| so that they are readily removed upon removing the cover I2. I

The device shown in Figs. 7 and 8 is adapted to be disposed horizontally and have the gases flow therethrough in a horizontal direction. It comprises a cylindrical casing I5 having end walls I8 and 11 which may be bolted to flanges I8 at the ends of casing I5, by means of bolts 18 as shown. The interior of the casing is divided into three chambers 88, 8| and 82 by means of partitions 88 and 84.

The end walls and the partitions are provided with openings within which are mounted ioraminous, open-ended inlet tube and outlet tube 85. The openings are so arranged that the inlet and outlet tubes are offset laterally with respect to each other, and the inlet tube extends through chamber 88 and part-way through chamber 8|. In the same way, outlet tube 85 extends through chamber 82 and part-way through chamber 8|. Within chamber 8| the two tubes are arranged laterally adjacent one another for a portion of their lengths.

A baflle member is arranged within the lower portion of chamber 8|, this member comprising plate sections 81, 88, 88 and 88, mounted at their ends, as by welding, upon partitions 88 and 84, sections 81 and 88 being inclined downwardly toward each other and having their lower edges spaced apart to form an opening 8|. Sections 88 and 88 are arranged in a similar manner to form an opening 82. An opening 88 is provided in the bottom portion of the casing wall within chamber 8|, this opening being closed by means 01' a plate 84 which is fastened in place by bolts 85.

The operation oi this device is substantially similar to that of those described heretofore. The exhaust gases enter inlet tube 85 and pass therethrough into chamber 8|. During the course of this passage chamber 88, being connected to the interior of the inlet tube 85 by means of the perforations of the tube, functions as a resonator or expansion chamber and exerts a silencing action upon the gases. Within chamber 8| the gases may pass directly from inlet tube 85 to outlet tube 85 through the perforations of the tubes, but the predominant proportion of the gases emerge from the end of tube 85, reverse their direction and fiow backwardly .within chamber 8|, and reverse their direction again and flow into the end of tube 85 and through tube 85 to the atmosphere, During their passage through chamber 82 they are subjected to the silencing action of this chamber, the interior of which is connected to tube 88 by the perforations of the tube. Either one or both of chambers 88 and 82 may have sound-absorbing material therein surrounding the tubes. The reversals of gas fiow within chamber 8| serve to dislodge the solid particles from the gas stream by centrifugal force. Some of the particles are dislodged at the first reversal and those which do successfully follow the first reversal are dislodged at the second. In addition, the force of gravity causes separation of some particles during the relatively slow return flow of the gases within chamber 8|. The particles fall uponthe battle member in the lower portion of the chamber, and descend the inclined surfaces of the plate sections to the openings 9| and 82 and then fall to the zone of quiescence below the bafiie member. They may be cleaned out periodically by unscrewing bolts 85 and removing plate 94 and cleaning the particles-out through opening 83.

The construction of Fig. 9 is along lines similar to those of Figs. 5 and 6 and comprises a vertically disposed casing I88 having a transverse partition |8I dividing the casing into chambers I82 and I83. A foraminous inlet tube I84 extends upwardly into chamber I 82, and an outlet tube I85 passes through chamber I88 and extends downwardly into chamber I82. The portion of out-let tube I85 located in chamber I 82 and in the lower portion of chamber I88 is flattened at the side I85 which faces inlet tube I84, as shownin Fig. 10. The upper portion I81 of the tube is circular. The circular portion IN is imperforate, as shown in Fig. 9 and the fiat portion I85 is likewise imperforate, the rest of the tube wall being foraminous. An inclined baiile member I88 is located in the lower portion of chamber I82 and inclines downwardly from the portion of the casing wall near inlet tube I84 toward the remote portion of the casing wall. The lower end of baflle I88 is spaced a considerable distance from the casing wall to provide a relatively large opening I88 into the zone of quiescence. The lower portion of baffle member I88 is supported by a vertical partition I I8 which restricts the deposited particles to the space adjacent the opening and provides a resonating chamber III. A removable cover 2 is provided for the cleanout opening of the zone of quiescence.

In this modification the imperforate portion MB of outlet tube I05 prevents the exhaust gas from passing directly laterally from the inlet tube to the outlet tube and carrying solid particles with it into the outlet tube. As a consequence, a greater proportion of the gases flow downwardly and enter the open end of the outlet tube, and the effectiveness of particle removal is increased. At the same time, the perforated portion of the walls of the outlet tube facilitates flow of the gases into said tube after their direction has been reversed, and this results in less restriction to flow being offered by the device. Outlet tube I05 may be cylindrical throughout its entire length, in which case the half of it, approximately, which is disposed toward the inlet tube is imperforate and the balance foraminous. The flattened side has the advantage that when it is inserted into the correspondingly shaped opening in partition IOI it is insured that the imperforate side will be disposed properly toward the inlet tube.

The bafile member I08 extends beyond vertical partition H0 and over the zone of quiescence,

only a relatively short distance. It has been found that when the zone of quiescence is confined laterally by partition IIO a cushion of gas is created therein and a relatively large opening into it from above is permissible without causing the quiescence to be disturbed appreciably. This has the advantage that the deposit of solid particles into the zone is facilitated.

In Figs. 11 and 12 there is illustrated a construction which is along the line of Figs. 1 and 2, but which does not have the outlet tubes extending into the chamber. The casing I20 has end walls I2I and I22, end wall I22 being provided with an outlet opening I 23. A partition I2& is spaced inwardly from end wall I22 and a frusto-conical bafiie member is spaced interiorly from end wall I2I. Partition I24 divides the easing into chambers I26 and I21, and bafile member I25 provides a zone of quiescence I28 in the lower portion of chamber I26. Imperforate inlet tube I29 passes through inlet end wall I2l and baiile member I25 and into chamber I26.

Partition I24 is curved or dished and provided with a downwardly extending annular shoulder I30, which is located at a lower level than the upper end of inlet tube I29. This shoulder is provided with outlet openings in the form of slots I3I, as shown in Fig. 12. Baflle member I25 isv provided with slots I22 similar to the slots 22 of Fig. 2,

The exhaust gases pass upwardly through inlet tube I29 and against partition- I24 where they reverse their direction and flow downwardly within chamber I25. They again reverse their direction and flow upwardly through slots I3I in partition I 24. During this reversal of direction the solid particles are rejected by centrifugal action and fall upon baflle member I25 and descend the same and pass through slots I22 into the zone of quiescence I28 where they may be periodically cleaned out by removing plug I 33. The gases converge within chamber I21 and pass upwardly through outlet opening I23. This construction has been found to be effective for both the silencing and the spark removing functions.

Although one inlet tube and two outlet tubes are the most that are shown in the different modifications there may be any desired number of either, their size and number being regulated so that the device will handle the quantity of gas discharged by the engine with a minimum restriction to flow. Where the inlet and outlet tubes are referred to in the singular in the specification and claims, it is understood that this includes the plural as well,

I claim:

1. A combination silencer and solid particle separator comprising means forming a chamber, said chamber having inlet and outlet openings in opposite walls thereof, open-ended inlet and outlet conduits arranged in juxtaposed relation within said chamber, said inlet and outlet conduits being connected at one end thereof to said inlet and outlet openings respectively, and each extending from the wall opening to which it is connected part way toward the opposite wall and having an open end located within said chamber, said inlet and outlet conduits being arranged laterally adjacent one another throughout a portion of their length, the open ends of said inlet and outlet conduits located within said chamber being in free and unconfined communication with each other through the space within said chamber, the conduits extending from at least one wall of said chamber having openings in the walls thereof, and a baille member within said chamber below the open ends of said conduits within said chamber and in spaced relation to the bottom wall of said chamber, said baiile member defining a zone of quiescence therebeneath and being constructed to provide one or more openings for the passage of solid particles from the space above said baille member into said zone of quiescence.

2- The construction of claim 1 in which the inlet tube is in contact with and mechanically joined to the outlet tube along their juxtaposed portions.

3. A combination silencer and solid particle separator comprising means forming a chamber, said chamber having inlet and outlet openings in opposite walls thereof, open-ended inlet and outlet conduits arranged in juxtaposed relation within said chamber, said inlet and outlet conduits being connected at one end thereof to said inlet and outlet openings respectively, and each extending from the wall opening to which it is connected part way toward the opposite wall and having an open end located within said chamber, said-inlet and outlet conduits being arranged laterally adjacent one another throughout a portion of theirlength within said chamber, the open ends of said conduits being in free and unconfined communication with each other through the space within said chamber, the conduit extending from one wall of said chamber having openings in the walls thereof on the side remote from the conduit extending from the opposite wall, and a bafile member within said chamber below the open ends of said conduits within said chamber and in spaced relation to the bottom wall of said chamber, said baflle member defining a zone of quiescence therebeneath and being constructed and arranged to provide one or more openings for the passage of solid particles from the space above said banle member into said zone of uiescence.

4. The construction of claim- 3 in which the imperforate side of the conduit having openings in the walls thereof is flat.

5. A combination silencer and solid particle separator comprising means forming a chamber adapted to be disposed vertically, said chamber-having inlet and outlet openings in opposite walls thereof, open-ended inlet and outlet conduits arranged in juxtaposed relation within said chamber, said inlet and outlet conduits being connected at one end thereof to said inlet and outlet openings respectively. and each extending .from the wall opening to which it is connected part way toward the opposite wall and having an open and located within said chamber, said inlet and outlet conduits being arranged laterally adjacent one another throughout. the por-- ing constructed and arranged to provide communication for the passage of solid particles from the space above said baiile member into said zone of quiescence.

6. The construction of claim 5 in. which the inlet conduit is imperforate below said baflle.

member and has openings in the walls thereof above said baiile member.

7. A combination silencer and solid particle separator comprising means forming a chamber, said chamber having inlet and outlet openings in opposite walls thereof, open-ended inlet and outlet conduits arranged in juxtaposed relation duits extending from at least one wall of said chamber having openings in the walls thereof, a battle member within said chamber below the open ends of said conduits within said chamber and in spaced relation to the bottom wall of said chamber, said baflie member defining a zone of quiescence therebeneath and being constructed and arranged to provide communication for the passage of solid particles from the space above ,said baflle member into said zone of quiescence,

and one or more additional sound-suppressing chambers cooperatively associated with said conduits.

8. The construction of claim 1 in which the baiile member comprises one or more pairs of sections, the sections of each pair being inclined downwardly toward each other, said sections being arranged to provide one or more openings at the lowermost portions thereof for the passage of solid particles to said zone of quiescence.

9. A combination silencer and solid particle separator comprising means forming a chamber,

said chamber having inlet and outlet Openings in opposite walls thereof, open-ended inlet and outlet conduits arranged in juxtaposed relation within said chamber, said inlet and outlet conduits being connected at one end thereof to said I inlet and outlet openings respectively, and each extending from the wall opening to which it is connected part way toward the opposite wall and having an open end located within said chamber, said inlet and outlet conduits being arranged laterally adjacent one another throughout a por-' tion of their length, the open ends of said conduits being in free and unconfined communication with each other through the space within said chamber, the conduits extending from at least one wall of said chamber having openings in the walls thereof, a bailie member within said chamber below the open ends of said conduits within said chamber and in spaced relation to the bottom wall of said chamber, said baiile membcr defining a zone of quiescence therebeneath and being constructed and arranged to provide communication for the passage of solid particles from the space above said baflie member into said zone of quiescence, means for spraying water into the portion of said chamber surrounding said conduits, and'means for draining said water from said chamber.

10. A combination silencer and solid particle separator comprising means forming a chamber, said chamber having inlet and outlet openings in opposite walls thereof, open-ended inlet and outlet conduits arranged in juxtaposed relation within said chamber, said inlet and outlet conduits being connected at one end thereof to said inlet and outlet openings respectively, and each extending from the wall opening to which it is connected part way toward the opposite wall and having an open end located within said chamber, said inlet and outlet conduits being arranged laterally adjacent one another throughout a portion of their length, the open. ends of said inlet and outlet conduits locatedwithin said chamber being in free and unconfined communication with each other through the space within said chamber, the conduits extending from at least one wall of said chamber having openings in the walls thereof, and a baflie member within said chamber below the open ends oi said conduits within said chamber and in spaced relation to the bottom wall of said chamber, said baille member defining a zone of quiescence therebeneath and being constructed-to provide one or more openings for the passage of solid particles from the space above said baflie member into said zone of quiescence, the bottom wall of said chamber at said zone of quiescence having a clean-out opening therein.

11. A combination silencer and solid particle separator comprising means forming a chamber, said chamber having inlet and outlet openings in opposite walls thereof, open-ended inlet and outlet conduits arranged in juxtaposed relation within said chamber, said inlet and outlet conduits and outlet openings respectively, and each extending from the wall opening to which it is connected part way toward the opposite wall and having an open end located within said chamber, said inlet and outlet conduits being arranged laterally adjacent one another throughout a portion of their length, the open ends of said conduits being in free and unconfined communication with each other through the space-within said chamber, the conduits extending from at least one" wall of said chamber having openings in the walls thereof, a baflle member beneath the open ends of said conduits within said chamber being connected at one end thereof to said inlet and in spaced relation to the bottom wall of said 70 chamber, said baiile member being constructed and arranged to provide an opening for the passage of solid particles from above said Me member into the space below said opening, and a partition extending upwardly from ,the' bottom wall 16 of said chamber to said baflie member and being baifle member is attached to and supported by adapted to confine said solid particles to the the iniet conduit and extends laterally toward space adjacent said opening, the wall of said the walls 01 said chamber, but stops short of said chamber having a, clean-out opening therein prochamber walls to form an opening through which 5 viding access to said space. the particles may pass into the zone of quiescence. 5

12. The construction of claim 5 in which the ROBERT L. BOYLE. 

